Switch contact for circuit breakers



' D. R. DAVIES SWITCH CONTACT FOR CIRCUIT BREAKERS Filed June 14, 1923 WlINES i bei' for such devices which Patented Mar. 1, 1927,` l

l*PATENT OFFICE.

"DAVID REGINALD DAVIES, OF liIANCHESTER, ENGLAND, ASSIGNOR TO WESTING- HOUSE VANIA.

ELECTRIC isa-MANUFACTURING COMPANY, Aw CORPORATION 0F PENNSYL- swiren con'rno'r Eon lcmeurr BREAKERS.

Application led June 14, `1923.A Serial No. 645,228;

This invention relates t, electric switches, circuit closers and the like and has for its objectto provide an improved contact memshall have a large current'carrying capacity and at the same time be very flexible so as to permit of small movements or.` variations in the distance between the terminals of the 'switch or circuit closer when the circuit is closed andbetween which it affords a means of connection.

Another object of my invention is to provide aswitch Contact device that is particularly well adapted for use in disconnectin@- switches associated with .circuit breakers ol` end of the brush makes contact bythe edgesthe truck panel type wherein fixed contact members, that are mounted within the truck cell, are engaged by contact'members carried upon thejruck when the truck is moved into the cell. A

According to the invention, the improved contact member comprises a brush composed of plates of good electrically conductive material, said plates being mounted so that one of the plat-es with one terminal of the switch, the other ends of the plates being adapted to make contact with the other terminal .of

the switch or circuit closer.A T he plates are sov that the pressure between the.

arranged l two terminals of the switch or circuit closer when the circuit is closed 1s transmitted substantially in the direction of the longitudinal axes of the plates and, in order to secure flexibility and pei-mit of slight inovementsof the two terminals of the switch or circuit closer, the plates are curved so tha"L the ressure between the contact surfaces ten s to deforin said plates and to spread apart the edges of Ythe plates through which current is transmitted. l

1n order that the natur-e oi. the invention may be clearly understood, a method of cai'- rying out the same in practice -will now 'be described as applied by way of. example to dcvicesi'or making contact between electrical conductors one of which is moved towards aifd away from the other along an axis coininon to both conductors., as in the manner of disconnecting-switch contacts of a standard truck panel type circuit breaker.

Referring to the accompanying drawings,

Figure 1 is an elevation of such a device wherein lthe terminals of the device are shown in-open circuit.

Fig. 2 is an elevation of the said device wherein the terminals are shown in closed circuit and,

Fig.` 8 is a separate view of the improved contact.

Referring now to Fig. 1, two electrical conductors 1 andl 12 are vshown between which it is desired to make electrical contact. Vhere the contact conductors are used as a disconnecting switch, member of a truck panel ty e circuit breaker, the conductor 1 ispre erably carried 1i on the circuit breaker truck and thecon uctor 12 is mounted within the truck cell'in alinement with the conductor 1. By reason of this arrangement, the contact elements mounted on the conductor 1 are withdrawn from the cell with the truck and may readily be inspected and repaired.` The conductor 1 is provided with a Contact block 2 on which is mounted the improved contact member (shown separately in Fig. 3) comprising two-brushes 3 and 4 formed of a plurality of pla-tes or laminations or copper or any other suitable metal bent to any suitable curve. lThe plates are secured by means of screws 7 and 8 to the opposite sides of al support 5 and are so arranged` that the chord of the arc to which the are bent is parallel with the direction o movement of the movable conductor 1, that is to say ina horizontal direction as shown in the drawings. Suitable springs 9 and 10 are interposed between the heads of the screws and the sides of the conductor 12' is'provided with a contact block 11 having a plane contact face perpendicular to the direction of movement of said conductor and adapted to make contact with the exposed edges of thetwo brushes.

The operation of the swit h` or vcircuit closer. is as follows:

When the conductor 1 is moved to the left as shown in Fig. 2 to close thecircuit, the

esv

edges of the plates or laminations are pressed hardfagainst the plane faces ofthe contact blocks 2 and 11 and the plates then spread outwards to a small degree, causing what is known as'a wiping Contact.' At thesame time, the support 5 slides along the bolt 6 as shown in F ig. 2.

By the present invention, a contact'member is provided which hasal large current carrying capacity without at the same time being very bulky. Further, when the circuit is closed, a small amount of movement of the movable conductor may be made without opening the circuit, such movement only causing the edges of the lates of which the brushes are composed eit er to spread apart or close together slightly, the resistance to the passage of the current remaining substantially the same. Other advantages of the improved contact will be evident and it isito vbe understood that the arrangement of parts is not to be restricted to that herein'- y before set forth since various modifications the laminated plates and adapted to be flexed or bowed under tension when the 4conductor lates are moved into engagement with the rush. y

2. Switch mechanism comprising a pair of relatively movable conductor plates and a flexible contact brush comprising flexible laminated plates bowed in the form of an arc andv disposed between the plates in such manner that the chord of the aye is parallel with 'the plane in which the conductor plates are relatively movable and yieldingly making contact with the conductor plates respectively at opposite edges of the laminated plates.

3. Switch mechanism comprising a pair of' relatively movable conductor plates and Aa yielding Contact membercarried upon one .plates are moved toward each other.

4. Switch mechanism comprising a pair of relatively movable conductor plates and a yielding laminated conductive brush dis-- posed in end to end relation to the contact plates and movably carried by one of the plates for making wiping conductive Contact with the plates when the toward each other.

5. Switch mechanism comprising a pair of relatively movable conductor plates, and a conductive contact brush comprising a plurality of arcuate laminated brush members bowed in opposite directions and mountedupon a movable support for conductively en- Agaging the conductor plates at the respective ends of the members when the contact plates are Vmoved toward each other.

6. Switch mechanism comprising a pair of relatively movable conductor plates, a guide' carried by one of the plates and extending in the direction of movement of the plates, a' support mounted for movement upon the guide and movable in the plane of movement of the conductor plates, and a bowed exible conductor element mounted on the support for conductively engaging the conductor plates with the end edge; thereof when `the plates are moved toward each other.

.In testimony whereof, have hereuntol subscribed my namethis 30th day of May DAVID REGINALD DAVIES.A

plates are moved 

